Allison Transmission Inc. hasn't given up on going public, despite nearly eight months passing since its initial filing with the Securities and Exchange Commission.

The Indianapolis-based manufacturer updated its prospectus on Nov. 4 to reflect financial results through Sept. 30 that show the company made more profit in the first nine months of this year than in all of 2010.

Allison still hasn't said how many shares it will issue at what price, but as long as it keeps its financial information current, the Securities and Exchange Commission will allow the company to complete its IPO, said David Menlow of IPO Financial in Millburn, N.J.

In practice, the longer it takes to set terms, the more likely the IPO will never launch, he said. "That's the biggest problem."

Allison spokeswoman Melissa Sauer said the company would not comment on when it might complete the IPO.

Allison announced its intent to go public in March, potentially raising $750 million.

Another local company, Angie's List Inc., by contrast, announced its intent to go public in August and on Nov. 2 priced the shares at $11 to $13.

Menlow thinks Delphi Automotive Plc's pending IPO could give Allison a lift. Delphi, based near Detroit, said on Nov. 7 that its shares would likely go for $22 to $24, and a person familiar with the offering told Bloomberg News that they could start trading as early as Nov. 17.

"If Delphi is received well in the marketplace, the chances of Allison moving forward improve," Menlow said. Both companies are former units of General Motors, and investors tend to lump them in with the whole automotive industry," he said.

Allison, which makes transmissions for heavy-duty trucks and buses, reported a profit of $58.5 million through Sept. 30, compared with $5.5 million in the same nine-month period last year. It earned $29.6 million in all of 2010.

Sales have increased 12 percent, from $1.47 billion to $1.6 billion, in the nine-month period, Allison reported. Another factor behind the surge in profitability is lower interest expense.

Allison reduced its total debt this year from $3.7 billion to $3.46 billion.