CINCINNATI (AdAge.com) -- Unilever has agreed to acquire Alberto-Culver Co. for $3.7 billion in cash in a deal that would create the clear No. 2 player in U.S. hair care to Procter & Gamble Co. and give Unilever one of the few U.S. personal-care businesses to have seen robust growth in the past year.

The deal, approved by boards of both companies but subject to regulatory and shareholder approval, would also make Unilever the global leader in hair conditioners, the company said, though it would remain No. 2 globally to P&G in shampoo. An estimated third of Alberto's $1.6 billion in sales comes from Tresemme, which has been the fastest-growing brand in U.S. mass hair care for the past few years and has been nipping at the heels of L'Oreal's Garnier Fructis to become No. 2 to P&G's Pantene in overall mass hair care.

Though Unilever is paying a relatively hefty 15 times cash flow for Alberto, it's a relatively rare acquisition that has initially boosted the stock of the acquirer, which was up 2.8% in early Monday trading in London.

Unilever said it remains committed to organic growth as primary driver of its business, and said personal care now accounts for 30% of its sales, up from 20% 10 years ago. Alberto has operations in nine countries now, but Unilever's strength in Asia and Latin America should make it easier to expand Tresemme into more markets there.

The addition of VO5 also bolster's Unilever presence in value hair care in the U.S., where it also sells Suave, and gives it additional value brands in the U.K. with VO5 and Tresemme, along with Simple, a U.K. natural beauty care brand Alberto acquired late last year. Other brands in the deal include St. Ives and Noxzema, the latter yet to receive a major restage push since Alberto acquired it from P&G in 2007.

To succeed with the deal, Unilever will have to avoid ending up with the same outcomes for acquired Alberto-Culver brands as it had for several brands acquired in its 1990s acquisition of Helene Curtis -- such as Finesse and Salon Selectives -- since divested to private-equity firms, and Thermasilk, folded into Sunsilk. The latter brand, launched in 2006, has struggled to remain on shelves of U.S. retail chains in the past year, though Dove, Suave and Axe have kept Unilever's U.S. hair-care shares stable overall in the U.S. in the past year.

The deal could render largely moot a recent global media review, with final country assignments between Carat and Maxus yet to be determined, according to Alberto-Culver. Unilever's North American shop, WPP's Mindshare, handles Unilever's North American media. Alberto spent $240 million globally on advertising last year, according to financial reports.

Mullen, Winston-Salem, N.C., and Arnold, New York, split Alberto's global creative assignments in June. Neither of those agencies is currently on Unilever's roster.

Though Unilever hasn't announced plans for Alberto-Culver's marketing staff, it's currently in the process of consolidating its own Chicago-based marketers with the rest of the company's U.S. operations in Englewood Cliffs, N.J.