Continued soft ad sales led Tribune Co. to lower its second-quarter profit forecast by 26% to 22 cents a share and to announce plans to cut 1,400 jobs, mainly at its newspaper operations, through layoffs and voluntary retirements. Including broadcasting, entertainment and interactive units, consolidated revenue through May 27 was down 6%, it said. At Tribune Publishing, which operates the No. 2 U.S. newspaper group by revenue, national ad revenue was off 9% for the year through May 27, classified off 14% and retail unchanged. In trading Friday, Tribune closed at $40.19, off 3.76% for the week. Among AdMarket 50 companies, only six were up, 43 were down and one unchanged last week.