The Federal National Mortgage Assn. raised the...

The Federal National Mortgage Assn. raised the maximum limit on conventionally financed single-family mortgages that the company may buy to $153,100, effective Jan. 1 . . . Security Pacific signed a definitive agreement to acquire Portland, Ore.-based Orbanco Financial Services and its Oregon Bank subsidiary for $47 million . . . Jet America said it will pull out of Burbank Airport next week, ending service to Las Vegas . . . May Department Stores said it will take a fourth-quarter pretax charge of $14 million to cover the early retirement of debentures due in 2015.