UPDATE 2-MFA Mortgage Q2 profit quadruples

(Recasts; adds details, share movement, analyst comments, conference call details)

By Adheesha Sarkar

July 30 (Reuters) - Mortgage real estate investment trust MFA Mortgage Investments Inc (MFA.N: Quote, Profile, Research) posted a more than four-fold rise in second-quarter profit, missing analysts' estimates by a cent, helped by a rise in income from investment securities.

The quarterly earnings were in-line with expectations, given the effect of a $304 million public equity offering the company made in June, which increased the size of their portfolio by almost 30 percent, analyst Steven Delaney from JMP Securities said by phone.

"In doing that, they set themselves up for a really strong third quarter, when the earnings on the new assets acquired would be fully realized for the first time," Delaney said.

Delaney said the key driver in earnings was the expansion in net interest spread to 138 basis points from 90 basis points. MFA expects an interest spread of 155 basis points in the third quarter, the company said in a conference call.

HYBRID MORTGAGE-BACKED SECURITIES

MFA increased its hybrid and adjustable-rate mortgage-backed securities' portfolio by $2.4 billion during the quarter.

The company is building on to its existing book with similar assets they have earned previously, said Delaney adding, "this is an excellent time to be an investor in additional hybrid mortgage-backed securities."