Ford Motor has certainly given investors plenty to cheer about: its first North American operating profit in more than four years and positive cash flow.

Its credit ratings, however, remain bottom of the barrel, a reminder that management’s bold move to mortgage the company to the hilt during the credit boom, while life saving, also means the company has little room to maneuver.

A $23.8 billion cash cushion should keep emergency fund-raising at bay. Yet Ford is likely to keep eyeing the equity market to meet its obligations to retirees.

That the automaker could continue tapping stock investors is testament to how far Ford has come after it unveiled its turnaround plan in 2006. It, unlike General Motors [GM.UL] and Chrysler, survived the slide in auto sales without needing additional funds from the government or court protection from its creditors.

And its share price has more than tripled since the beginning of the year — even with the 300 million share sale in May.

Fitch Ratings analyst Mark Oline expects Ford to return to the equity market opportunistically. That could mean, for example, stock issuance to help finance a $2 billion obligation to its retiree health care trust, VEBA, by year-end. The company used some of the proceeds from the earlier stock sale to make such contributions.

Fitch today upgraded Ford’s longer-term outlook to positive from stable but kept its credit rating at CCC — indicating its still precarious position even with the improvement in cash flow. The company has to clear a number of hurdles, including maintaining or increasing its market share and managing its impressive debt load, before Fitch will consider lifting its ratings.

Ford had debt of $26.9 billion as of the end of September. In 2011, the year the company faces a maturing bank agreement, Barclays Capital estimated last month that gross debt should stand at 3.5 times EBITDA, significantly higher than GM’s 1.3 times.

Ford’s third-quarter results deserve applause, but they’re far from eliciting the standing ovation the company will need to restore the leading role in credit markets it once enjoyed.

[UPDATE - Moody's Investors Service on Monday raised its ratings on Ford and its finance arm, citing the automaker's progress in cutting costs and boosting market share.]