Chase Manhattan Mortgage Corp. was the top issuer of Ginnie Mae mortgage securities during the hectic first three months of 2001, turning out a heavy $3.14 billion of new production, according to a new market analysis by Inside Mortgage Finance. Chase, the second-largest Ginnie Mae issuer for all of last year, pushed its issuance up 40.4 percent over the same period in 2000, giving it a 10.43 percent market share. Last year’s top issuer, Wells